Secrets Based On Trust
by GoldGuardian2418
Summary: Sans finds out about Rachel's and Sasha's powers.


**This story came to me one day and was inspired by many of the Undertale stories on this site. :)**

 **Undertale belongs to Toby Fox. Ben 10 belongs to Cartoon Network and Man of Action. I only own Rachel, Megan, and Sasha. Summer and Forrest belong to VinnieStokerLover.**

* * *

 **Secrets Based On Trust**

Sans had heard a lot of rumors in Staybrook as he walked down the alleys.

"That Rachel girl has powers from what I hear," said a person. "Dangerous powers."

"She can control animals into attacking us," said another person.

"What about her sister? She can make plants do unnatural things, like making a dead tree suddenly become healthy again."

"What if they are witches? Or users of black magic?"

The shorter skeleton scoffed at that, but he did feel Rachel and Sasha did have abilities that very few humans were known to have. He also felt it when trying to read what their dominant traits were, but he could only sense a little of their traits and wondered why.

He was heading over to the Grant Mansion anyway to pick up Frisk, so he decided to talk to Rachel and Sasha when he got there.

Teleporting to the front door, he knocked. "I'll get it!" He heard Rachel call out before she opened the door. "Oh, hi, Sans!" She said brightly, letting him come in. "I'll go get Frisk."

"Actually, Rachel, I need to talk to you," he said.

She looked at him and noticed how serious his expression was. "Sans? Is everything alright?" She asked.

"I need you to call Sasha and find a place for us to talk privately," he said.

Sensing the urgency in his voice, Rachel was about to call out Sasha's name when her sister came downstairs. "Hi, Sans," she greeted him with a smile, but noticed that the shorter skeleton seemed very serious. "Um, is everything okay?" She asked.

Rachel indicated to the living room, which was empty at the moment and they went inside, sitting down. Sans took a deep breath. "I heard some rumors in town and they got me a bit worried, as well as something I've been sensing about you two for a bit now," he said.

The sisters looked at each other. "Which rumor did you hear?" Rachel asked.

He arched an eyeridge at her. "You're not surprised?" He asked.

"The Grant Mansion does have a 'haunted' reputation," Sasha explained. "Besides, a lot of people don't like us or our uncles and have been spreading rumors about our family for a long time."

"We're pretty used to it by now," Rachel said. "Although there's been occasions when some of the aliens have had to deal with the people spreading the rumors, but even then, it's not enough to stop people from saying nasty things about us."

Sans frowned a little before taking a deep breath. "The rumor was that you two have powers," he said. "Something about controlling animals or making dead trees come to life."

Both sisters' faces fell. "Oh, great," said Sasha with a groan. "Maybe I should make thorn bushes grow in those jerks' homes."

"What good would that do?" Rachel asked softly. "Those gossipers are just as bad as the Forever Knights. The only difference is we can whoop the Forever Knights, but not the gossipers."

After a moment, Sans spoke. "So, you two do have powers?" He asked.

They nodded. "Yes, we do," Sasha said. "When Rachel and I were very little, our uncle found an injured alien, Chromastone, and helped him. As a reward, our uncle was given the ability to talk to animals."

"He then asked if the alien, a Celestialsapien, would grant me and Sasha powers too," Rachel explained. "I was also given the ability to talk to animals and Sasha was given the ability to control plants."

"But we didn't find out about our powers until we were older," Sasha explained. "We were in our late teens when we either discovered our powers or were told about them."

The older girl nodded. "I also have a ghostly wail," she said. "It's a powerful scream that can knock down buildings if I make it loud enough."

The hoodie-wearing skeleton was curious now, as it sounded like the two knew their powers and how to use them. "I'm going to ask you girls another question, but this one is based on absolute trust," he said. "You girls are aware about monsters seeing a person's soul, right?"

The two nodded. "Whampire mentioned that a scientist named Alphys had spoken to the Plumbers about that," Sasha said. "You find out a person's dominant traits that way, right?"

Sans nodded and Rachel knew where he was going with this. "You want to see our souls," she said in realization.

Sasha looked confused. "How?" She asked.

"This is where the absolute trust comes in," Sans said seriously. "I'm going to initiate a FIGHT sequence."

Rachel looked worried. "Sans, we don't want to fight you," she said in concern.

"Why would we fight you?" Sasha asked. "You're not an enemy."

Their words made Sans pause before looking at them seriously again. "Like I said, it's based on absolute trust," he said. "Do you girls trust me?"

The sisters looked at each other before Rachel looked at him. "Sans, we won't fight," she said, stepping forward until she was right in front of him. "You've proven you're trustworthy to us."

He looked at her. "If you really trust me, then go through the FIGHT sequence with me," he said. "The actions you chose will decide if it'll be a fight, or simply talking."

Sasha looked at Rachel and then at Sans, biting her lip thoughtfully. "Sounds a bit like when we met some of the aliens," she said. "Depending on what we chose…,"

"The aliens would judge us on our actions," Rachel finished for her.

They nodded to each other and took each other's hand and turned to Sans, nodding in unison.

Taking a deep breath, Sans initiated the FIGHT sequence.

But before the fight could begin, Sans gasped in shock, catching the sisters' attention and they looked at him curiously, seeing him cradling something in his hands and he looked at them. "You…You two need to see this," he said and showed them two hearts in his hands. The two hearts each had seven colors, colors that were familiar to the two girls.

"They look like rainbow hearts," Rachel said in awe.

The hoodie-wearing skeleton looked at them. "I have never seen this before," he admitted. "You girls have all the seven traits that monsters have admired for years in the Underground."

Sasha looked at him. "What seven traits are those?" She asked.

"Determination, bravery, justice, kindness, patience, integrity, and perseverance, in the order of a rainbow's colors," Sans answered. He then gestured to a box-like screen in front of the sisters. "Select the 'ACT' button, and then select 'SPARE'," he guided them.

Rachel selected the 'ACT' button and Sasha selected the 'SPARE' option, sparing Sans, who let go of the rainbow-colored souls, which went back to the sisters and gently disappeared to where they belonged.

The owner of the Grant Mansion then looked at Sans. "Sans, was that…power you were using too?" She asked.

"We monsters call it magic," he explained. "But yeah, we monsters have power too."

He then looked at them. "I'm sorry, girls," he said. "I…,"

"Wanted to put your mind at ease after hearing those rumors," Sasha said gently. "You're not the first one, Sans. Rachel and I have reassured our children, nieces, and nephews many times after they hear some ugly rumors."

The skeleton looked at them. "I know your alien friends have powers, but do any of the other humans living here have powers too?" He asked.

"My daughter, Summer, and my son, Forrest, do," Rachel said. "Summer has wind powers and Forrest has super strength."

"My daughter, Megan, has the ability to control plants like me," Sasha said. "Rachel, Rook, Whampire, and I grew worried about our children being the target of our enemies and felt that if they had some kind of power, it would give them a chance to get away from our enemies."

Sans nodded understandingly. "You girls haven't told people outside of your family about your powers, have you?" He asked curiously.

"Only a handful of people that we trust and have helped us many times," Rachel said.

He nodded again. "Okay," he said before giving them an apologetic look. "Still, I'm really sorry I thought you two weren't being truthful."

The sisters smiled. "Secrets are based on trust, Sans," Sasha said with a smile. "And we trust you unwaveringly."

Sans smiled at them. "You two are the only humans besides Frisk that have earned my full trust," he said.

Smiling, the three shared hugs before Rachel and Sasha looked at Sans mischievously. "I think we've got _a bone to pick with you_ , Sans," said Rachel.

" _Tibia_ honest, your rib bones!" Sasha said, grinning.

Sans' eyes grew wide at that and he lifted his hands to protect himself, but that unfortunately gave the girls access to his ribcage and they wasted no time tackling the skeleton to the floor and tickling his ribs.

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Frisk, who had been playing a game with Summer, heard her dunkle's laughter and her face lit up. "Dunkle Sans is here!" She said excitedly. "Come on, Summer!"

The five-year-old girl followed her older cousin to the living room where they saw Sans squirming helplessly on the floor as Rachel and Sasha tickled him mercilessly. "Good thing we have experience tickling skeletons, huh, Rach?" Sasha said.

"A _skele-ton_ of experience," Rachel answered her sister.

Frisk and Summer giggled at that and at Sans' loud laughter.

"AHAHAHAHAHAHAHAHAHAHAHAHAAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!" Sans laughed out before the sisters decided he had enough and let him up.

The skeleton sat up and saw Summer and Frisk come up to him and hug him. He returned the hugs with a chuckle. "What happened?" Frisk asked curiously.

"Oh, just your dunkle, my sister, and I messing around with each other, honey," Sasha said with a smile.

The children giggled in amusement as Sans stood up and picked them up in his arms. "Yeah, they gave me a good _rib-tickling,"_ he said with a chuckle. "I thought I'd _fall to pieces_ there for a moment."

The sisters chuckled. "Don't worry, Sans," Rachel said with a smile and a friendly wink. "We may _rattle your bones,_ but we'll make sure you're always our _punny_ friend."

Sans laughed in amusement, returning the friendly wink. "And I'll _keep you two in stitches_ with my puns," he said.

The five shared a warm laugh together.

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 **The story where Rachel and Sasha find out how they got their powers is called "Past And Present", which can be found on my page.**

 **Please leave a review, but no flames!**

 **GoldGuardian2418**


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